This invention relates to a method of separating hydrocarbons and other organic materials from fabrics such as shop rags.
Conventional shop rags are typically made of woven cotton fabrics as well as nonowoven fabrics, and these rags are used in the industry to wipe up oil, grease and solvents, or to clean parts with hydrocarbons and other solvents. These reusable rags are then laundered, using sufficient detergent and high temperature and agitation to emulsify hydrocarbons.
There is increasing governmental regulation in the field of cleaning of soiled rags and garments, and there is a limitation on the amount of hydrocarbons which may be discharged to a sewer.
In order to deal with these problems, special cleaning procedures have been developed, usually involving extraction of the soiled item with a volative organic solvent. Such methods require recovery of the solvent and subsequent evaporation to separate the hydrocarbons and are not entirely satisfactory. Examples of various proposals may be found in U.S. Pat. Nos. 5,222,267, 5,207,922, and 5,112,358.
An example of a disposable fabric may be found in U.S. Pat. No. 5,207,837. Here, the fabric is made from fibers of polyvinyl alcohol. After use, the fabric is placed in a hot water bath and heated to a temperature above 37.degree. C. to dissolve the fabric in the water, whereupon the water is passed into a sewer.